Centrifugal rpm regulator for internal combustion engines

ABSTRACT

A centrifugal rpm regulator for internal combustion engines is provided with at least two angular, centrifugal weights. Each centrifugal weight includes an angled lever and a centrifugal mass fixedly connected to one lever arm of the angled lever. The opposite lever arm actuates a regulating sleeve. Each lever has a bearing location in the region of connection of its two lever arms by means of which the centrifugal weights are pivotally mounted on a centrifugal weight carrier. The lever arm to which its centrifugal mass is connected has an irregular shape. The centrifugal masses desirably consist of metal which can be diecast and surrounds the irregularly shaped arm.

United States Patent Bechstein et al.

[ July 22, 1975 Robert Bosch G.m.b.H., Stuttgart, Germany Filed: Dec. 11, 1973 Appl. No.: 423,743

[73] Assignee:

[30] Foreign Application Priority Data Dec. 23, 1972 Germany 2263382 U.S. Cl. 73/550 Int. Cl. G05d 13/14 [58] Field of Search 73/535, 550

[56] References Cited UNITED STATES PATENTS 278,387 5/1983 Badger 73/550 X 2,856,479 10/1958 Fletcher 73/550 X Primary Examiner.lames J. Gill Attorney, Agent, or Firm-Edwin E. Greigg ABSTRACT A centrifugal rpm regulator for internal combustion engines is provided with at least two angular, centrifugal weights. Each centrifugal weight includes an angled lever and a centrifugal mass fixedly connected to one lever arm of the angled lever. The opposite lever arm actuates a regulating sleeve. Each lever has a bearing location in the region of connection of its two lever arms by means of which the centrifugal weights are pivotally mounted on a centrifugal weight carrier. The lever arm to which its centrifugal mass is connected has an irregular shape. The centrifugal masses desirably consist of metal which can be die-cast and surrounds the irregularly shaped arm.

10 Claims, 5 Drawing Figures CENTRIFUGAL RPM REGULATOR FOR INTERNAL COMBUSTION ENGINES BACKGROUND OF THE INVENTION This invention relates to a centrifugal rpm regulator for internal combustion engines, the regulator being of the type having at least two angular centrifugal weights. More particularly, the present invention relates to a centrifugal rpm regulator for internal combustion engines having at least two angular centrifugal weights, whose centrifugal masses are, respectively, fixedly connected to one lever arm of a respective angled lever, the opposite lever arm of the angled lever actuating a regulating sleeve, and the lever having a bearing location in the region of the connection of the two lever arms by means of which the centrifugal weights are pivotably mounted on a centrifugal weight carrier.

In known centrifugal force rpm regulators of the above-mentioned construction, the angular centrifugal weights are either made entirely of cast iron, of a forged steel piece or a section of profile steel, or they are assembled by mechanically fastening a centrifugal mass, essentially composed of two constructional parts, to an angled steel lever. The centrifugal weights used in the abovve-mentioned known regulators require very expensive treatment or expensive manufacturing techniques in order to achieve the desired, predetermined characteristic curve of centrifugal force .vs. rpm because of the required precision of that curve. For example, it is desired that the characteristic curve of centrifugal force vs. rpm bulge toward its top, because this has an advantageous effect on the idling stability of the regulator. For this purpose, it is necessary that the operative mass of the centrifugal weights be concentrated, as much as possible, in the region of the outermost end of the lever arm of the angled lever.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a centrifugal rpm regulator for internal combustion engines which is inexpensive to manufacture in large quantities.

It is another object of the present invention to provide a centrifugal rpm regulator for internal combustion engines which has masses which can be diecast directlyon a lever arm of the regulator.

It is an additional object of the present invention to provide an inexpensive centrifugal rpm regulator for internal combustion engines which achieves a desired, predetermined characteristic curve of centrifugal force vs. rpm and results in a good idling stability for the regulator.

It is a further object of the present invention to provide an inexpensive centrifugal rpm regulator for internal combustion engines which achieves a desired, predetermined characteristic curve of centrifugal force vs. rpm, the curve exhibiting a desired bulge toward its top.

It is still another object of the present invention to provide a centrifugal rpm regulator for internal combustion engines which avoids the need for constructing centrifugal weights from cast iron, forged profiled steel or multiple parts which need to be assembled about an angled steel lever.

The foregoing objects, as well as others, which are to become clear from the text which follows, are accomplished by providing a centrifugal rpm regulator for internal combustion engines which includes a centrifugal weight carrier and at leasst two angular centrifugal weights. Each centrifugal weight includes l an angled lever having a first arm and a second arm, the second arm having at least a portion thereof of irregular shape, (2) a bearing location in the region of connection of the first arm and the second arm which serves to mount pivotally the respective centrifugal weight to the centrifugal weight carrier, and (3) an angular centrifugal mass fixedly connected to the first arm, which mass surrounds at least that portion of the first arm having the irregular shape. A regulating sleeve is operatively positioned to be actuated by the second arm.

It is a salient novel feature of the present invention that the one arm of the angled lever has an irregular shape. Thus, operative masses of the centrifugal weights may readily consist of metal which can be diecast and which surrounds this arm of the lever.

It is possible to achieve a very good, robust union between the metal and the one arm of the lever because the outer profile of the one arm of the lever has preferably sawtooth-like projections which are surrounded by the mass of the centrifugal weight.

Furthermore, it is also advantageous that the one arm of the lever has at least one cavity or bore which is filled with metal of the centrifugal weight mass. By means of the afore-mentioned cavity, either alone or in combination with the sawtooth-like outer profile of the one arm of the lever, a very good union is achieved between the weight mass of the centrifugal weight and the angled lever.

For highly stressed centrifugal rpm regulators, an advantageous embodiment of the invention is provided by making the angled lever of steel and hardening it in a region of a pressure surface where it cooperates with the regulator sleeve. In less severely stressed centrifugal rpm regulators an inexpensive arrangement of parts can be achieved by providing that the angled lever is pressed of sintered steel.

It is furthermore advantageous if the material of the centrifugal weight mass consists of a zinc alloy which can be die-cast because, in this way, a short manufacturing period can be achieved, while maintaining the highest possible precision.

A stable bearing for the centrifugal weight and a good anchoring of the centrifugal weight mass is achieved, in an advantageous further development of the present invention, in that a portion of the mass of the centrifugal weight surrounds a bearing sleeve serving as a bearing location.

The angled lever, in a particularly advantageous embodiment, is eccentrically connected to the bearing bushing and the one arm of the lever, which is surrounded by the centrifugal mass, is bent toward the center of mass of the centrifugal mass.

In another advantageous embodiment, the one arm of the angled lever to which the centrifugal mass is fastened, is itself fastened separately from the other lever arm in a plane of the center of mass of the centrifugal mass, on the bearing bushing.

BRIEF DESCRIPTION OF THE DRAWING Three exemplary embodiments of a centrifugal rpm regulator, according to the invention, are illustrated in the drawing and are described further below.

FIG. 1 is a cross-sectional view through constructional parts of the first exemplary embodiment of a centrifugal rpm regulator according to the present invention.

FIG. 2 is'a side elevational view of a corresponding centrifugal weight, associated with a lever of the exemplary embodiment illustrated in FIG. 1.

FIG. 3 is a sectional view taken along section line III- III of FIG. 2.

FIG. 4 is a cross-sectional view of a centrifugal weight mass and lever which could be used in a second exemplary embodiment of the present invention, this view corresponding to a view taken along section line IVIV of FIG. 3.

FIG. 5 is a cross-sectional view similar to that of FIG. 4 for a third exemplary embodiment.

DESCRIPTION OF THE PREFERRED A EMBODIMENTS Referring now to FIG. 1, a centrifugal rpm regulator for an internal combustion engine, according to the present invention, has a drive shaft and a preferably square extension 11 which carries thereon a centrifugal weight carrier 12. The weight carrier 12 is held in the illustrated position by a springing disc 13 and a safety ring 14. Fixedly connected to the centrifugal weight carrier 12 are pivotal bearings 15 which accept respective bearing bolts 16 on which two centrifugal weights 17 are pivotably mounted. These centrifugal weights 17 have an angled construction and consist of an angled lever 18 made of steel, of a bearing bushing 19 and of a centrifugal weight mass designated 20, only one lever being shown in detail for the purpose of clarity.

The material for the centrifugal mass 20 preferably consists of a zinc alloy material capable of being diecast (see especially FIGS. 2 and 3) which material is applied around a lever arm 21, equipped with sawtooth-like projections, the arm 21 being part of the angled lever 18. A portion of the centrifugal weight mass designated 20a (FIGS. 2, 3) also surrounds the bearing bushing 19 fixedly connected to the angled lever 18 and serves as a bearing location. In order to improve further the anchoring of the centrifugal weight mass 20 to the lever arm 21 of the angled lever 18, this lever arm 21 has a cavity 22 embodied as a bore. Because this cavity 22 is filled with the metal of the centrifugal weight mass 20 after the die-casting of the lever arm 21, a very robust, solid connection of the centrifugal weight mass 20 to the angled lever 18 is achieved.

In addition to the lever arm 21, the angled lever 18 also has a second lever arm 23 which is preferably hardened in the region of a pressure applying surface 25 which cooperates with a regulating sleeve 24. If lower strength requirements are made with respect to the durability of the angled lever 18, it may be pressed of sintered steel.

The regulating sleeve 24, at its end 26 adjacent to the lever arm 23 carries, in known fashion, a thrust bearing 27 and is itself carried in known fashion on a bearing stud 28 rigidly connected to the drive shaft 10. The regulating sleeve 24 is loaded, in a known and therefore not further described fashion, either directly or indirectly, and via intermediate levers, by at least one regulating spring.

As is shown in FIG. 4, a second exemplary embodiment of a centrifugal weight 17' includes one lever arm designated 21 which forms part of an angled lever 18 which is eccentrically connected with the bearing bushing 19, is bent toward the middle of the centrifugal weight 17 or toward the center of mass of the centrifugal weight mass 20, in order to achieve a better distri- 5 bution of the material of the centrifugal weight mass 20 around the lever arm 21. A one-sided distribution could cause undesirable stress cracks.

The same purpose is served by the separate disposition of two lever arms 21" and 23" forming part of an angled lever 18" on the bearing bushing 19 in the third exemplary embodiment, as shown in FIG. 5. One lever arm 21 is fastened in the plane of the center of mass, i.e. in the middle of the centrifugal weight 17" on the bearing bushing 19.

The mode of operation of the centrifugal weights l7, l7 and 17 sometimes designated as pendulum centrifugal weights, of the centrifugal rpm regulator according to the invention, is known, and, in order to achieve a characteristic curve of centrifugal force vs. rpm which has a bulge toward the top, the mass of the centrifugal weight mass 20 is very largely concentrated at that end of the lever arm 21, 21' or 21", as the case may be, which is the further away from the bearing bushing 19. In this manner, very good regulation can be achieved at low rpm; yet it is possible to manufacture the rather complicated external shape of the centrifugal weights very precisely using die-casting techniques with the result that a post-production treatment or finishing operation is unnecessary. In turn, this makes possible a very inexpensive mass production which, nevertheless, achieves sufficient precision.

It is to be understood that the foregoing description and the illustrated preferred embodiments have been given not as limiting embodiments but as examples. Many other embodiments and varients are possible within the spirit and scope of the invention, the scope being defined in the appended claims.

That which is claimed is:

1. A centrifugal rpm regulator for internal combustion engines comprising, in combination:

a. a centrifugal weight carrier;

b. at least two angular centrifugal weights, each said centrifugal weight including:

1. an angled lever having a first arm and a second arm, said first arm having at least a portion thereof of irregular shape,

2. a bearing location, defined by a bearing bushing, in the region of connection of said first arm and said second arm serving to mount pivotally the respective said centrifugal weight to said centrifugal weight carrier, and

3. an angular centrifugal mass, a portion of which surrounds said bearing bushing, fixedly connected to said first arm and surrounding at least that portion of said first arm having said irregular shape; and

c. a regulating sleeve operatively positioned to be actuated by said second arm.

2. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said centrifugal mass is die-cast about said first arm.

3. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said portion of said first arm having said irregular shape exhibits an outer profile of sawtooth-like projections, said projections being surrounded by said centrifugal mass.

4. A centrifugal rpm regulator for internal combustion engines as defined in claim 3, further including a cavity or bore in said one arm, said cavity or bore being filled with metal of said centrifugal mass.

5. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said irregular shape is provided, at least in part, by at least one cavity or bore in said one arm, said cavity or bore being filled with metal of said centrifugal mass.

6. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is of steel and has a hardened region where it contacts said regulating sleeve.

7. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is pressed of sintered steel.

8. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said mass is formed of a zinc alloy.

9. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is eccentrically connected to said bearing bush ing, said first arm of said lever being bent toward the center of mass of said centrifugal mass.

10. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said one arm of said angled lever is fastened, separately from said second arm, in a plane of the center of mass of said centrifugal mass, on said bearing bushing. 

1. A centrifugal rpm regulator for internal combustion engines comprising, in combination: a. a centrifugal weight carrier; b. at least two angular centrifugal weights, each said centrifugal weight including:
 1. an angled lever having a first arm and a second arm, said first arm having at least a portion thereof of irregular shape,
 2. a bearing location, defined by a bearing bushing, in the region of connection of said first arm and said second arm serving to mount pivotally the respective said centrifugal weight to said centrifugal weight carrier, and
 3. an angular centrifugal mass, a portion of which surrounds said bearing bushing, fixedly connected to said first arm and surrounding at least that portion of said first arm having said irregular shape; and c. a regulating sleeve operatively positioned to be actuated by said second arm.
 2. a bearing location, defined by a bearing bushing, in the region of connection of said first arm and said second arm serving to mount pivotally the respective said centrifugal weight to said centrifugal weight carrier, and
 2. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said centrifugal mass is die-cast about said first arm.
 3. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said portion of said first arm having said irregular shape exhibits an outer profile of sawtooth-like projections, said projections being surrounded by said centrifugal mass.
 3. an angular centrifugal mass, a portion of which surrounds said bearing bushing, fixedly connected to said first arm and surrounding at least that portion of said first arm having said irregular shape; and c. a regulating sleeve operatively positioned to be actuated by said second arm.
 4. A centrifugal rpm regulator for internal combustion engines as defined in claim 3, further including a cavity or bore in said one arm, said cavity or bore being filled with metal of said centrifugal mass.
 5. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said irregular shape is provided, at least in part, by at least one cavity or bore in said one arm, said cavity or bore being filled with metal of said centrifugal mass.
 6. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is of steel and has a hardened region where it contacts said regulating sleeve.
 7. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is pressed of sintered steel.
 8. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said mass is formed of a zinc alloy.
 9. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said angled lever is eccentrically connected to said bearing bushing, said first arm of said lever being bent toward the center of mass of said centrifugal mass.
 10. A centrifugal rpm regulator for internal combustion engines as defined in claim 1, wherein said one arm of said angled lever is fasteneD, separately from said second arm, in a plane of the center of mass of said centrifugal mass, on said bearing bushing. 